Indirect study of 12C(α, γ)16O reaction. Issue 1 (January 2016)

• Record Type: Journal Article
• Authors: Hammache, F; Oulebsir, N; Roussel, P; Pellegriti, M G; Audouin, L; Beaumel, D; Bouda, A; Descouvemont, P; Fortier, S; Gaudefroy, L; Kiener, J; Lefebvre-Schuhl, A; Tatischeff, V
• Is Part Of: Journal of physics. Volume 665:Issue 1(2016)
• Publication Date: 2016-01
• Subjects: Physics -- Congresses; 530.5
• DOI: 10.1088/1742-6596/665/1/012007
• Languages: English
• ISSNs: 1742-6588

Abstract

Abstract: The radiative capture reaction 12 C(α, γ) 16 O plays an important role in helium burning in massive stars and their subsequent evolution [1]. However, despite various experimental studies, the cross section of this reaction at stellar energies remains highly uncertain. The extrapolation down to stellar energy (E cm ∼300 keV) of the measured cross sections at higher energies is made difficult by the overlap of various contributions of which some are badly known such as that of the 2+ (E x =6.92 MeV) and 1 − (E x =7.12 MeV) sub-threshold states of 16 O. Hence, to further investigate the contribution of these two-subthreshold resonances to the 12 C(α, γ) 16 O cross section, a new determination of their a-reduced widths and so their a- spectroscopic-factors was performed using 12 C( 7 Li, t) 16 O transfer reaction measurements at two incident energies and a detailed DWBA analysis of the data [2]. The measured and calculated differential cross sections are presented as well as the obtained spectroscopic factors and the a- reduced widths as well as the assymptotic normalization constants (ANC) for the 2+ and 1 − subthreshold states. Finally, the results obtained from the R-matrix calculations of the 12 C(α, γ) 16 O cross section using our obtained a-reduced widths for the two sub-threshold resonances are presented and discussed.